Passengers rate the next time they open the app. It could be any time immediatly after the ride was ended, or any point in the future, when they open the app again to request a car, which could be a few days/weeks later. So your rating going down was probably a passenger who you took a while ago, who then rated you.

Passengers rate the next time they open the app. It could be any time immediatly after the ride was ended, or any point in the future, when they open the app again to request a car, which could be a few days/weeks later. So your rating going down was probably a passenger who you took a while ago, who then rated you.